Akysis

Hendrickson's stream catfish, Akysis hendricksoni, is a small akysid catfish from much of Peninsular Malaysia and the extreme south of Thailand. One of the few members of the family exported for the hobby, it grows to around 50 mm SL and spends some of its time buried in sand with only the eyes showing. Colour pattern varies with locality, and like many fishes from running water it is intolerant of organic pollutants and needs spotless water.

The Sittaung stream catfish, Akysis longifilis, is a small akysid catfish known from the Sittaung River system in southern Myanmar. One of the few members of the family exported for the hobby, it has noticeably long nasal and maxillary barbels and two saddle-shaped light markings between the dorsal and caudal fins. The sympatric A. portellus is very similar, and differs mainly in its shorter adipose fin base and smaller mouth.

The spotfin stream catfish, Akysis maculipinnis, is a small akysid catfish from Chanthaburi Province in eastern Thailand. Its range apparently extends into Cambodia. Among the smaller members of the family at around 35 mm SL, it has been exported for the hobby. It spawns above the substrate in flowing water with no parental care, and the adults are avid egg-eaters, so the eggs must be protected if fry are to be raised.

The smallmouth stream catfish, Akysis portellus, is a small akysid catfish from the Sittaung River system in southern Myanmar. One of the few members of the family exported for the hobby, it grows to around 43 mm SL. It closely resembles the sympatric A. longifilis, and differs in its shorter adipose fin base, smaller mouth and more rounded head when viewed from above.

The Indawgyi stream catfish, Akysis prashadi, is an akysid catfish from Lake Indawgyi and the upper Ayeyarwady drainage in northern Myanmar. It has also been recorded from the Lokchao river in Manipur, India. At up to 62 mm SL it ranks among the largest in the genus, and though it has been exported for the hobby it is by no means common.

The Kra stream catfish, Akysis pulvinatus, is a small akysid catfish from southern Thailand. Known from streams on the western side of the Kra Isthmus and the upper Tapi basin, it grows to around 30 mm SL and has been exported for the hobby on an extremely limited basis. It most resembles A. vespa, and differs in its longer adipose fin base, deeper caudal peduncle and a caudal fin with the lower lobe longer than the upper.

The variable stream catfish, Akysis varius, is a small akysid catfish from the Mekong drainage in Laos, Thailand and Cambodia. The number of serrations on its pectoral spine varies, and in contrast to other Akysis with serrated spines, the larger specimens examined had fewer or none. Members of the genus live almost exclusively in swiftly flowing streams and rivers over sand, gravel and rocks.

The orange-banded stream catfish, Akysis vespa, appears endemic to headwaters of the Salween basin on the border between Myanmar and Thailand. One of the few members of the family exported for the hobby, it is also sold as 'wasp catfish' or 'orange micro bumblebee catfish'. Its yellow markings normally form wide bands, a pattern rarely seen in congeners, and the yellow on the snout extends to the base of the nasal barbels.

The western stream catfish, Akysis vespertinus, is an akysid catfish known only from the Ann Chaung river system in Rakhine State, western Myanmar. Exceptionally rare in the aquarium trade, it has a narrow snout that makes the head look triangular, and two light, saddle-shaped markings between the dorsal and caudal fins. The region holds several other locally endemic fishes, including Danio aesculapii, and the species seems likely to occur more widely there.